The present invention relates to a new and improved construction of apparatus for doubling of fiber webs.
Generally speaking, the fiber web-doubling apparatus of the present development is of the type comprising web transport means, a web collecting or collector element, and a so-called diverter plate arrangement for deflecting or turning the web from the transport or conveying direction of the web transport means into the transport or conveying direction of the web collecting element.
Doubling, that is superposing fiber webs so as to form a new single web, serves for evening these webs with regard to length and to the blend of the staple fibers which form the web.
Apparatuses of the aforementioned type which serve for such doubling operations are primarily used on so-called ribbon lap machines which are commercially known from spinning machines. In such ribbon lap machines a plurality of laps arranged adjacent one another supply their respective fiber webs into a drafting mechanism where the web is drawn and is thereafter immediately guided over a so-called diverter plate arrangement.
By means of this diverter plate arrangement the drawn fiber webs are superposed so as to form a new fiber web composed of all of the drawn webs of the same machine.
Additionally, the apparatus can be used on so-called sliver lap machines which bring together a plurality of drawn fiber slivers into a web and double these individual web so as to form a new web.
Such a sliver lap machine has been disclosed in Swiss Pat. No. 375,640, granted Feb. 29, 1964 and the corresponding U.S. Pat. No. 3,128,506, granted Apr. 14, 1964. This sliver lap machine comprises fiber sliver drafting mechanisms arranged next to one another and to which there are delivered fiber slivers from sliver cans or the like.
The fiber slivers which are drawn in the drafting mechanisms are combined or amalgamated into a web and following each drafting mechanism are guided by means of a diverter plate arrangement on to a collecting surface for all of the webs. The diverter plate arrangement is arranged adjoining the drafting mechanism viewed with respect to the transport direction of the web. The individual webs, collected to form a new web, are guided to a wind-up apparatus for the formation of a lap.
The previously discussed ribbon lap machines have a construction resembling that of the sliver lap machines except that laps are used as the web feed in place of the sliver cans delivering fiber slivers. In other words, the individual drafting mechanisms do not draw fiber slivers, as is the case for the sliver lap machines, but webs delivered by the lap. The individual drawn webs are collected so as to form a new web in the same manner as in the sliver lap machines and are also guided to a wind-up apparatus for the formation of a lap. The laps of the ribbon lap machines thereafter serve as the feed or stock for the combing machines.
The described construction of the sliver lap machine, and also that of the ribbon lap machine, is afflicted with the drawback that due to the disposition of the diverter plate arrangement in front of the drafting mechanism, as viewed from the service side of the machine, leading in of the staple fiber slivers or lap ribbons, as the case may be, cannot be carried out unless the machine attendant or operator first guides the staple fiber slivers or the webs into the infeed rolls of the drafting mechanism from the back of the machine and thereafter seizes or catches at the front of the machine the webs delivered from the drafting mechanisms and guides them over the diverter plate arrangement.